Pool materials

Vinyl liner. Lowest entry price, at $130–$240 per square foot installed per This Old House, or $35,000–$80,000 for a typical build per Thursday Pools. The liner is a consumable: Thursday Pools puts replacement at $3,000–$7,500 every 5 to 15 years. Ten-year maintenance runs $11,000–$17,000 per This Old House.

Fiberglass. A factory-made shell dropped into an excavation, $175–$330 per square foot installed. Thursday Pools' dealer survey puts small shells (under 26 feet) around $74,000, medium (27–34 feet) around $109,000 and large (35 feet and up) near $113,000. It is the cheapest of the three to run: $5,000–$15,000 over ten years. The trade-off is that you choose from a catalog of shapes and sizes.

Concrete or gunite. Any shape you can draw, and the highest cost at both ends: $200–$350 per square foot to build, $50,000–$120,000 or more per Thursday Pools, and $27,000–$40,000 over ten years per This Old House. Expect acid washing at $300–$1,000 every 3 to 5 years and resurfacing at $8,000–$10,000 every 10 to 15 years. Those are not defects — they are the normal service schedule for a concrete pool.

How to choose

Match material to how long you will stay

If you plan to move in under ten years, the lower maintenance load of fiberglass matters less than the build price. If this is your forever home, concrete's resurfacing cycle will show up more than once.

Fiberglass shells have a delivery constraint

The shell arrives in one piece on a truck and needs crane or equipment access. Confirm your lot can physically take it before you fall in love with a model.

Ask about the liner warranty separately

Read the actual liner document rather than a salesperson's summary — coverage, proration and exclusions vary and only the contract counts.

Budget the concrete service schedule up front

Acid washing every 3-5 years and resurfacing every 10-15 years are predictable expenses. Put them in the plan rather than treating them as surprises.

Don't choose on square-foot price alone

Ranges overlap heavily. A well-specified vinyl pool can cost more than a small fiberglass one; compare complete quoted scopes.